Roof-supporting assemblies

ABSTRACT

AN HYDRAULIC SELF-ADVANCNG ROOF-SUPPORTING ASSEMBLY FOR USE IN UNDERGROUND WORKINGS SUCH AS COAL MINES HAVING A COMPENSATING DEVICE IN ITS UPPER PART. THIS COMPENSATING DEVICE COMPRISES AN HYDRAULIC RAM ARRANGED TO ACT LONGITUDINALLY OF THE ASSEMBLY AND TWO TRANSVERSELYARRANGED HYDRAULIC ALIGNING CYLINDERS, THE COMPENSATING DEVICE AS A WHOLE BEING SO MOUNTED ON THE ASSEMBLY THAT IT PIVOTABLE IN THREE DIFFERENT PLANES.

Feb. 9, 1971 H w. EIAL 3,561,221 ROOF-SUPPORTING ASSEMBLIES Filed Oc t. 14, 1969 s SheetsSheet 1 I 7 52 Q 5 JMQM 5 i m A 4 Inventors. HANS BULL,

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g HAN-S United States Patent ()ffice 3,561,221 Patented Feb. 9, 1971 3,561,221 ROOF-SUPPORTING ASSEMBLIES Hans Biill, Wuppertal-Elberfeld, and Alfred Maykemper, Wuppertal-Barmen, Germany, assignors to Herman Hemscheidt Maschinenfabrik, Wuppertal-Elberfeld, Germany, a German body corporate Filed Oct. 14, 1969, Ser. No. 866,277 Claims priority, application Germany, Oct. 23, 1968,

P 18 04 611.2 Int. Cl. E21d 15/44 US. Cl. 61-45 4 Claims ABSTRACT OF THE DISCLOSURE An hydraulic self-advancing roof-supporting assembly for use in underground workings such as coal mines having a compensating device in its upper part. This compensating device comprises an hydraulic ram arranged to act longitudinally of the assembly and two transverselyarranged hydraulic aligning cylinders, the compensating device as a whole being so mounted on the assembly that it is pivotable in three diiferent planes.

This invention relates to hydraulic self-advancing roofsupporting assemblies for use in underground workings such as coal mines.

Such assemblies generally comprise a pair of frames each of which has an upright hydraulic prop at the front and an upright hydraulic prop at the rear, the two frames being advanced alternately in a stepwise manner by means of a doubleacting hydraulic ram extending longitudinally of the assembly between the two frames. Normally the said ram is arranged in the lower part of the assembly and acts on the lower portions of the frames.

It has already been proposed in roof-supporting assemblies of the above construction to provide a compensating device which is connected to the upper portions of the four upright hydraulic props. This compensating device comprises a second frame-advancing hydraulic ram which extends, like the lower ram, longitudinally of the assembly so that the two rams are more or less parallel with each other. In addition, the compensating device includes two hydraulic aligning cylinders which act substantially at right-angles to the axis of the second frame-advancing ram. In operation of the assembly, the second frame-advancing ram and the two hydraulic aligning cylinders of the compensating device serve to counteract any top-heaviness of the two frames, this being especially important in those situations where the floor of the underground working is inclined.

Hitherto the compensating device described above has been articulated to two cylindrical guide rods interconnecting the props of the two frames so that the compensating device is pivotable in a vertical plane. In this way it is possible for the props of one frame to be extended or retracted independently of the props of the other frame Without the compensating device hindering such adjustment of the props. Similarly, it is also possible with the said arrangement to arrange the props of one frame at a different level or height from the props of the other frame without stressing the compensating device and its connections to the frames.

A disadvantage, however, of this particular arrangement is that its ability to pivot in one plane only is a serious limitation in certain operations of the roof-supporting assembly as a whole. Thus, for example, it is not possible with such a compensating device for one of the frequently necessary, particularly where difficult geological conditions prevail or where there is unevenness in the floor or roof of the underground working. It is also necessary at times to arrange the props temporarily in positions where they are inclined at widely-differing angles with respect to one another. In the form of construction described above, such deviations of one of the props from the position taken by the remaining props is possible only to a very limited extent, this being determined by the amount of play in the articulated connections between the compensating device and the frames. Furthermore, it all too frequently happens that a part of the roof-supporting assembly is permanently deformed if one or more of the props is positioned or adjusted beyond the amount of play inherent in the above construction.

The aim of the present invention is to provide a roofsupporting assembly wherein the compensating device is so connected to the two frames that pivotal movement in more than one plane is provided, and according to the invention an hydraulic self-advancing roof-supporting assembly for use in underground workings comprises a pair of frames each having an upright hydraulic prop at the front and an upright hydraulic prop at the rear, a frame-advancing hydraulic ram extending longitudinally of the said assembly between the two frames and connected to the lower portions thereof so as to enable the ram to advance the frames alternately in a step-wise manner, a compensating device connected to the upper portions of the upright props so as to lie beneath the upper ends of the said props, the said compensating device comprising a second frame-advancing hydraulic ram extending longitudinally of the assembly and two axially-pivotable hydraulic aligning cylinders extending transversely of the said second ram with one end of each aligning cylinder being connected to the said second ram, a pair of guide rods extending between the upper portions of the front and rear props of the respective frames, the said rods being pivotally connected at their ends to the respective props for up and down pivotal movement, a pair of socket heads connecting the other ends of the said aligning cylinders to one of the guide rods whereby the cylinders are capable of pivotal movement about the said guide rod, a lateral projection on the said second ram having pivotal connections with the other one of the guide rods whereby the lateral projection is capable of pivotal movement about the last-mentioned guide rod, and a pivotal connection between one of the aligning cylinders and the socket head associated therewith whereby relative pivotal movement about an upright axis is provided between the said socket head and its associated aligning cylinder.

By means of the present invention, the compensating device is now articulated to the props so as to be pivotable in three different planes. As a result, the stability of the assembly is greatly improved and it is better able to assume a perpendicular position in relation to the floor of the underground working without the risk of damage to the assembly or injury to the personnel operating it. This means, in practice, that the roof-supporting assembly can be used where the seams of material being mined are geologically disturbed or uneven. Further, when one of the props is set in a position so that it has a different length from the other props, the compensating device is able to adjust itself accordingly because of its ability to pivot in three planes.

An example of an hydraulic self-advancing roof-supporting assembly in accordance with the invention is shown in the accompanying drawings, in which:

FIG. 1 is a plan view from above of the lower part of the assembly;

FIG. 2 is another plan view, similar to FIG. 1, showing the lower part of the assembly in a different working position;

FIG. 3 is a side view of the lower part of the assembly shown in FIG. 1;

FIG. 4 is a section taken on the line IV-IV in FIG. 1;

FIG. is an enlarged plan view from above of the upper part of the assembly showing the compensating device; and

FIG. 6 is a perspective view of the upper part of the assembly.

The hydraulic self-advancing roof-supporting assembly shown in the drawings is for use in underground workings such as coal mines and comprises a pair of frames 1 and 2 which are capable of being advanced relatively to each other in a step-wise manner, the direction of advance being shown by the arrows in FIGS. 1-3. Each frame includes a pair of spaced-apart upright hydraulic props, the frame 1 having two props 3 and 5 and the frame 2 having two props 4 and 6. As shown in FIGS. l-3, the props of each frame are rigidly connected together at their lower ends by rigid plates or bars 32 and 33 respectively.

Arranged between the lower portions of the two frames is a longitudinally-extending, double-acting, hydraulic ram assembly 34 which serves, in operation of the assembly, to advance the frames in a step-wise manner over the floor of the underground working. An outer cylinder 35 of the ram assembly 34 is rigidly connected to a horizontally-extending transverse plate 36 which is bolted by bolts 37 to the mid-portion of the longitudinally-extending plate or bar 33. This means that the props 4 and 6 of the frame 2 are mounted for movement with the outer cylinder 35 of the ram assembly during the step-wise advance of the roof-supporting assembly as a whole. In like manner, an inner cylinder 38 of the ram assembly 34 is rigidly connected to a horizontally-extending transverse plate 39 which is bolted by bolts 40 to the mid-portion of the longitudinallyextending plate or bar 32 and which projects through a lateral slot 41 (see FIG. 4) in the outer cylinder 35. As a result, the props 3 and 5 of the frame 1 are mounted for movement with the inner cylinder 38 of the ram assembly during advance of the roof-supporting assembly.

The construction described above enables the frame 1 to advance while the frame 2 remains stationary as the ram assembly 34 is extended to the position shown in FIG. 1. The frame 2 then remains stationary while the ram assembly 34 is retracted so as to pull the frame 1 level with the frame 2. The process is then repeated, with the result that the roof-supporting assembly advances in a step-wise manner. It will be appreciatd that the frames 1 and 2 are held stationary alternately by extending the upright props of the stationary frame and retracting the upright props of the frame to be moved. As will be seen, the lower ends of the upright props, 3, 4, 5 and 6 are supported by soleplates 42.

FIGS. 5 and 6 show the upper part of the roof-supporting assembly. From these it will be seen that a compensating device interconnects the upper portions of the frames 1 and 2 below the roof-lining girders or beams (not shown for the sake of clarity) which are supported on the upper ends of the props 3, 4, 5 and 6. The compensating device comprises a second frame-advancing hydraulic ram 11 extending longitudinally of the roofsupporting assembly and a pair of transversely-extending hydraulic aligning cylinders 18 and 19 which act perpendicularly to the frame-advancing ram 11. The frameadvancing ram 11 is protected in two tubes 9 and 10 one of which lies within the other. These two tubes are similar to the tubes 35 and 38, the inner tube 9 having a laterally-projecting cantilever plate 12 provided at its outer edge with two aligned eyelets or sockets 13 and 14 through which a cylindrical guide rod 15 extends so as to be rotatable in the eyelets. In order that the plate 12 may project outwards from the inner tube 9, the outer tube 10 has a lateral slot (not shown) in exactly the same way as the tube 35 is provided with a lateral slot 41.

The outer tube 10 is connected in an articulated manner to another cylindrical guide rod 22 by the hydraulic aligning cylinders 18 and 19 and by socket mountings or heads 20 and 21 at the ends of the said cylinders, the latter being rotatable about their axes in protective tubes 16 and 17. The socket head 20 is rotatable by means of a swivel pin 23 about one end of the front aligning cylinder 18, while the socket head 21 is rigidly connected to one end of the rear aligning cylinder 19. A strut 24 extends between the outer tube 10 and the protective tube 16 of the front aligning cylinder 18 so as to transmit the advancing motion imparted to the frame 2 by the ram 11 in a manner such that bending stresses are resisted. In contrast to this, the protective tube 17 of the rear aligning cylinder 19 is pivotably connected to the outer tube 10 through the intermediary of a forked head 25 having a pivot pin 43 which passes through a radial flange 44 on the tube 10. Further, the socket head 21 is capable of limited sliding movement along the guide rod 22.

As a result of this arrangement, the compensating device is articulated to the guide rods 15 and 22 in such a manner as to be pivotable in three different planes about the axes x, y and 2 which extend at right-angles to each other. These axes are defined:

(a) In the x direction by the hydraulic aligning cylinders 18 and 19 which are axially pivotable within their protective tubes 16 and 17;

,(b) In the y direction by the cylindrical guide rods 15 and 22 together with the socket heads 20 and 21 which are pivotable about these guide rods 15 and 22 or by the eyelets 13 and 14 of the cantilever plate 12; and

(c) In the z direction by the swivel pin 23 together with the socket head 20 which can swing about the swivel pin 23.

The guide rods 15 and 22 which support the compensating device are articulated at their ends to the upper parts of the props 3, 4, 5 and 6 by way of horizontal swivel pins 26, 27, 28 and 29 carried in forks 45, 46, 47 and 48 located on the upper parts of the said props so that each prop can be expanded and contracted independently of the other props, as well as being movable with respect to the other props to a limited extent. With a view to effecting longitudinal compensation of the distances separating the props from each other, the rear ends of the guide rods 15 and 22 are longitudinally shiftable in cylindrical bores 49 and 50 formed in forked elements 30 and 31 connecting the rods to the forks 47 and 48, it being understood that the elements 30 and 31 could equally well be at the front ends of the guide rods 15 and 22.

We claim:

1. An hydraulic self-advancing roof-supporting assembly for use in underground workings, comprising a pair of frames each having an upright hydraulic prop at the front and an upright hydraulic prop at the rear, a frame-advancing hydraulic ram extending longitudinally of the said assembly between the two frames and connected to the lower portions thereof so as to enable the ram to advance the frames alternately in a step-wise manner, a compensating device connected to the upper portions of the upright props so as to lie beneath the upper end of the said props, the said compensating device comprising a second frame-advancing hydraulic ram extending longitudinally of the assembly and two axiallypivotable hydraulic aligning cylinders extending transversely of the said second ram with one end of each aligning cylinder being connected to the said second ram, a pair of guide rods extending between the upper portions of the front and rear props of the respective frames, the said rods being pivotally connected at their ends to the respective props for up and down pivotal movement, a pair of socket heads connecting the other ends of the said aligning cylinders to one of the guide rods whereby the cylinders are capable of pivotal movement about the said guide rod, a lateral projection on the said second ram having pivotal connections with the other one of the guide rods whereby the lateral projection is capable of pivotal movement about the last-mentioned guide rod, and a pivotal connection between one of the aligning cylinders and the socket head associated therewith whereby relative pivotal movement about an upright axis is provided between the said socket head and its associated aligning cylinder.

2. A roof-supporting assembly as claimed in claim 1, wherein an end of each guide rod is mounted for longitudinal movement in a bore formed in a forked element which is pivotally connected to the upper part of a respective upright.

3. A roof-supporting assembly as claimed in claim 1, wherein the rear end portion of the frame-advancing ram in the compensating device has one of the aligning cylinders pivotally attached thereto.

4. A roof-supporting assembly as claimed in claim 1, wherein a strut is provided between a protective tube for one of the aligning cylinders and an outer tube of the frame-advancing ram in the compensating device so as to make the compensating device resistant to bending stresses.

References Cited UNITED STATES PATENTS 3,174,289 3/1965 Rosenberg 61-45 3,435,620 4/1969 Weirch et a1. 61-45 FOREIGN PATENTS 1,427,580 12/ 1965 France 61-45 1,126,821 4/1962 Germany 61-45 1,161,834 1/1964 Germany 6145 1,232,909 1/1967 Germany 6145 1,242,173 6/1967 Germany 6145 DENNIS L. TAYLOR, Primary Examiner 

